Machine for the heat treatment of earth roads and surfaces



Oct. 12, 1937. R. H. IRVINE MACHINE FOR THE HEAT TREATMENT OF EARTH ROADS AND SURFACES Filed Aug. 17, 1934 2 Sheets-Sheet l Ipyenzor L. H. H. IRVINE Oct. 12, 1937. L. R. H. IRVINE MACHINE FOR THE HEAT TREATMENT OF EARTH ROADS AND SURFACES 2 Sheets-Sheet 2 Filed Aug. 17, 1934 R. H. IRVINE Patented Oct. 12, 1937 UNITED STATES MACHINE FOR THE HEAT TREATMENT OF EARTH ROADS AND SURFACES Lionel Robert Herborn Irvine, Killara, Sydney, New South Wales, Australia -Application August 17, 1934, Serial No. 740,287 In Australia August 22, 1933 Claims.

It is known that, by applying heatto earth, clay or the like material, such materials can be altered so as to convert them into a substance similar to brick the hardness of which depends on 5 the degree of heat applied and other factors in connection with the heating.

In certain localities difficulties are experienced in obtaining materials such as stone and gravel for making roads and in such localities roads have to be left unconstructed on account of the prohibitive cost of transporting road material over long distances. Large areas of country subject to this disability are found in inland plains where the only material available is the natural soil. It so happens that the soil in such areas is claylike in character and roads made of it become plastic and impassable to traffic during and for some time following wet weather. The machine, the subject of the present application, is for applying heat to the natural earth road surfaces thus rendering them nonplastic and better capable of carrying traffic in varying weather conditions.

The machine which is the subject of the present application is the result of experiments carried out by the inventor both in the laboratory and in experimental road work in the field and is considered to be the most suitable at present known for the purpose described.

The machine comprises a furnace mounted on a carriage on wheels which moves along an existing earth road or prepared surface converting the surface layer of earth into bricklike material as it goes. The wheels may be provided with caterpillar tracks or crawlers if necessary. The machine is propelled under its own power and is provided with air blowers which supply air by forced draught for the combustion of the fuel in the furnace and for other purposes described hereunder. At the front of the machine is a scarifier for the purpose of making cracks or v voids in the ground to facilitate penetration of the heat. One arrangement of the machine is shown in the accompanying drawings, in which:

Fig. 1 is an elevation view, with parts in section, of the forward half of the machine, and

Fig. 1a is a similar view of the rearward half.

In the illustration the machine is resting on the earth surface under treatment. The ma- 50 chine moves in the direction from A to B. C is the frame or chassis and D the wheels. The front wheels are mounted on a swivel or swivels and are connected with a control, mechanism generally indicated at Zby which the machine is steered when in motion. The rear wheels are mounted on an axle through which the machine may be driven by transmission of power from the power unit designated by P.

Suspended within the chassis is another frame E which will be referred to as the sub-frame. The sub-frame carries the furnace and the subsidiary equipment connected with it. It is suspended from the chassis by three screws F, two

I of which are shownin the drawings, by means of which it can be raised or lowered as required, and by means of the separate raising or lowering of these screws it can be adjusted to fit closely over the surface under treatment, as required.

The upper or primary combustion chamber G g the bottom so that when suspended over the surface to be treated the latter forms the bottom of the chamber the heat from which is transferred to it. Forced draught is applied at the top of the primary combustion chamber from a blower Q by means of a duct J and also at the back of the secondary combustion chamber from a blower by means of a duct K. The draught from the blower through the duct K also has the effect of carrying the heat forward to L near the front of the machine where the gases of combustion enter the duct U and are discharged into the atmosphere through a flue M. The production of the forced draught may be accomplished by one or a plurality of blowers. As shown a single blower Q is employed. The action of M may be supplemented by a blower which draws the gases from the furnace. As the machine travels over the road the latter is subjected to the heat while it is passing under the space from L to I. The front and sides of the secondary combustion chamber are sealed to the road surface, as well as may be, by flexible chain doors, sliding metal plates or a similar suitable device.

The illustration shows the structure for sealing the machine to the road by means of metal plates V which rest upon the surface and which are free to slide up and down between guides W. As the machine moves the plates slide on the earth surface and are kept in contact with it by their own weight. They accommodate themselves to irregularities in the ground and they constitute a more or less heat proof seal between the sides of the secondary combustion chamber and the surface. X are small chains hung close together on rods Y fixed across the front and rear of the secondary combustion chamber. As the machine moves the chains trail over the surface maintaining contact with it and form a more or less heat proof seal at the front and rear of the secondary combustion chamber. The chains at the rear may be dispensed with. The function of the chains may be similarly performed by metalplates hinged to the rods Y.

In order to obtain more thorough heating of the earth in the secondary combustion chamber a scarifying attachment or a contrivance similar to a chain grate may be fitted within the secondary combustion chamber th object of such attachment or contrivance being to temporarily lift the earth while it is undergoing treatment.

The primary and secondary combustion chambers are lined with firebrick or other heat resisting material and such lining is carried forward towards L as far as may be necessary to protect the metal framework of the machine from the intense heat generated in the combustion chambers. The air from the duct K passes over, and to some extent through, the spaces in the heated material under the rear. part of the machine thus tending to cool it. The heat thus extracted from the material is conserved by'being blown back into the secondary combustion chamber to supplement the effect of the direct combustion of the fuel. This air also provides oxygen for the combustion of any fuel, solid or gaseous, which may pass from the primary to the secondary combustion chamber without havmg been consumed in the former.

The firebrick lining of G and I is suspended from girders which are part of the sub-frame. The power unit P and the blower or blowers are mounted at the front end of the machine in order to be free from any heat and products of combustion which may escape in the vicinity of the combustion chamber at the rear end. By this arrangement all driving clutches, flexible belts, etc. for transmission purposes are preserved from the effects of excessive heat. A dividing wall R, shown in section, is placed between the power unit, blowers and other incidental machinery and the flue M to further prevent over-heating ofsuch power units, blowers and other machinery.

This, wall or partition extends forward from one end S to T.

.O is a frame carrying a scarifier consisting of metal bars or spikes projecting downward into the ground. As the machine moves forward the spikes. break the ground making cavities into which the flames and hot gases can penetrate during the passage of the machine thus facilitating the'heating process. The spikes are sharpened as required to produce the eiiect most suitable for the particular soil under treatment or they may be replaced as required with discs similar to those on a disc plough or by any other device for cutting or opening up the ground. These are mounted on a frame which can be raised or lowered as required. They 'may be mounted on a revolving shaft or drum attached to the frame.

The machine is driven forward by power from the engine P transmitted either from the rear wheels onto the road or through a drum attached to the front of the machine on which is wound a cable made fast to an anchorage in the road ahead of the machine.

The transmission of power is through any well known mechanism such as shafts, pinions, chains, belts, worm gearing, etc. The transmission includes a variable gear which will permit of the rate of movement being varied within the approximate range of from 10 feet per hour to 5 miles per hour.

The machine may have a covering material extending wholly or partially over it, or may be covered wholly or partially by a roof of noninfiammable material such as sheet iron.

I claim:-

1. A machine for constructing non-plastic roads by heat-treatment of earth and other surfaces in situ, comprising a frame, a carryingmember therefor, another frame within the first frame, a furnace carried by the second frame, said furnace having two combustion chambers, said chambers being lined with heat-resisting material and connected with one another, one being lower than the other, the lower chamber being open at the bottom so that heat from it can be applied to the surface over which it is located, a power unit, and blower means operated by said unit for supplying air under pressure to the top of the upper combustion chamber and to one end of the lower combustion chamber. 1

2. A machine as claimed in claim 1, in which the sides and ends of the lower combustion chamber have means to enable them to make close contact with the surface over which the furnace is suspended, said means consisting of guides attached to the sides of the second frame and a plurality of metal plates free to move up and down between said guides.

3. A machine for constructing from earth, nonplastic roads by heat-treatment in situ of said earth,comprising a frame,carrying-wheels therefor, another frame inside the first frame, a furnace carried thereby, said furnace having two combustion chambers lined with heat-resisting material and connected with one another, one being lower than the other, the lower chamber being open at the bottom so that heat from it can be applied to the surface over which it is suspended, a power unit, blower means operated thereby'for supplying air under pressure to the top of the upper combustion chamber and to one end of the lower combustion chamber, and transmission mechanism connected to said power unit for operating the blower means and for also propelling the machine.

4. A machine for constructing from earth by heat-treatment thereof in situ, non-plastic roads,

comprising a frame, carrying-wheels thereforf another frame, a furnace carried thereby, said furnace having two combustion chambers lined with heat-resisting material and connected with one another, one being lower than the other, the lower chamber being open at the bottom so that heat from it can be applied to the surface over which it is suspended, a power unit, at least one blower, conduit means for conducting the blast of air from the blower to the top of the upper combustion chamber and to one end of the lower combustion chamber, means for operating the blower from the power unit, transmission mechanism connecting the power unit to the wheels to propel the machine through the wheels, the sides and ends of the lower combustion chamber havthe sides of the second frame, and a plurality of metal plates free to move up and down between said guides.

5. A machine for constructing non-plastic roads by heat treatment thereof in situ on the 5 read-to-be, consisting of a frame, carrying-wheels therefor, another frame suspended therein, a furnace carried by the second frame, said furnace having two combustion chambers lined with heatresisting material and connected with one another, one being lower than the other, the lower chamber being open at the bottom so that heat from it can be applied to the earthen, untreated road. surface-to-be over which it is suspended, an upper inlet for fuel for combustion, a power unit, blower means operated thereby for supplying air under pressure to the top of the upper combustion chamber and to one end of the lower combustion chamber, whereby to generate heat in an 1 amount sufficient to change the nature of the 

